1. Field of the Invention
The present invention relates to a swivel hook assembly for joining webbing or the like to key rings, ropes or other various things.
2. Description of the Prior Art
Typical swivel hook assemblies of the type described are disclosed in Japanese Patent Publication No. 63-29124 and Japanese Utility Model Publication No. 62-27701. The conventional swivel hook assembly according to Japanese Patent Publication No. 63-29124 comprises a rectangular web-engaging frame having an engaging hole and a hook member including a hook body adapted for securing a ring or the like and a coupling member mounted at one end of the hook body for coupling the hook body to the engaging hole of the web-engaging frame. The coupling member comprises a pair of opposed resilient engaging studs mounted substantially in a circle on one end of the hook body. The engaging stud has an outward-projecting prongs on its upper end. The outward-projecting prongs of the engaging studs are slightly greater in diameter than the engaging hole of the web-engaging frame. The outward-projecting prongs of the opposed engaging studs are forced through the engaging hole while compressed against their own resiliency and come into snap-fit engagement with the engaging hole so that the hook member is pivotally mounted on the frame.
The conventional swivel hook assembly according to Japanese Utility Model Publication No. 62-27701 is substantially identical with the preceding one except that the coupling member comprises four (not two) opposed resilient engaging studs mounted in a circle one one end of the hook member. After the outward-projecting prongs of the opposed engaging studs are forced through the engaging hole and come into snap-fit engagement with the engaging hole, a wedging member is wedged into the space between the opposed resilient engaging studs so as to prevent them from being compressed and coming off the engaging hole and thus augment the engagement of the engaging studs with the engaging hole.
However, these conventional swivel hook assemblies suffer from some drawbacks.
In the first type of conventional swivel hook assemblies, the two engaging studs are so thick and resilient that, once engaged with the engaging hole, they are retained in the hole very firmly, but much power is needed to force the two engaging studs through the engaging hole. On the other hand, in the second type, the four engaging studs are so thin and less resilient that little power is needed to force the four engaging studs through the engage hole, but they are likely to come off the hole when the swivel hook assembly is subjected to severe use. For ensuring the engagement of the engaging stud with the hole, this would require use of an extra wedging member, leading to increase in manufacturing cost.
Another disadvantage is shared by both types. The engaging studs, whether two or four, jointly assume a mushroom-like shape as a whole, and each have the outward-projecting prong on its upper end. If the studs were formed thick, this would require the outward-projecting prong to become the larger correspondingly. But, this must be avoided because it would be very difficult if not impossible to force the bulky projecting prongs through the engaging hole. This forces the engaging studs to be formed much smaller diameter than the engaging hole. Consequently, the engaging studs of the hook member are very loosely fitted into the engaging hole, so that they are very likely to be subject to distortion during use of the swivel hook, thus getting eventually damaged.